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101.
Abstract. Routine monthly samples of the commercially important portunid crab Liocarcimtx puber and the sympatric but ecologically separated L. holsatus were collected from the waters and shores around the Gowcr Peninsula, South Wales, between November 1983 and September 1985.
The pubertal moult in L. puber occurred at 38 mm CW (carapace width) (females) and 42 mm CW (males). In L. holsatus this occurred at 17 mm (females) and 18.5 mm CW (males). The median size of ovigcrous females was 49.2 ± 6.7 mm CW in L. puber and 26.5 ± 2.0 mm CW in L. holsatus.
Moulting and copulation occurred between spring and autumn, the moulting period of males being earlier than that of the females. Ovigcrous L. holsatus were recorded throughout the year, with highest proportions between February and April. L. puber were ovigcrous mainly between January and March; none was recorded between September and November. The number of eggs of the wild brood (range: 39,000–280,000 for L. holsatus and 40.000–262.000 for L. puber ) was related to female body size as y = 3.099.51 c0.1126x , r = 0.90, n = 21 and y = 6,335.98 c0.051x , r = 0.88, n = 23, respectively, where y = number of eggs and x = carapace width (mm).
Following successful copulation, females of both species were able to spawn more than once during an intcrmoult period. 相似文献
The pubertal moult in L. puber occurred at 38 mm CW (carapace width) (females) and 42 mm CW (males). In L. holsatus this occurred at 17 mm (females) and 18.5 mm CW (males). The median size of ovigcrous females was 49.2 ± 6.7 mm CW in L. puber and 26.5 ± 2.0 mm CW in L. holsatus.
Moulting and copulation occurred between spring and autumn, the moulting period of males being earlier than that of the females. Ovigcrous L. holsatus were recorded throughout the year, with highest proportions between February and April. L. puber were ovigcrous mainly between January and March; none was recorded between September and November. The number of eggs of the wild brood (range: 39,000–280,000 for L. holsatus and 40.000–262.000 for L. puber ) was related to female body size as y = 3.099.51 c
Following successful copulation, females of both species were able to spawn more than once during an intcrmoult period. 相似文献
102.
103.
104.
利用卫星遥感资料对南海北部陆架海洋表层温度锋的分析 总被引:4,自引:0,他引:4
利用7年(1993~1999)月平均的SST卫星遥感资料,分析了南海北部陆架区域海洋表层温度锋在一年中的逐月变化特征,表明南海北部陆架海洋表层温度锋存在明显的季节内变化。结合风场的卫星遥感资料,分析了东北季风对南海北部陆架温度锋的影响,表明东北季风风速的增加有利于温度锋强度的增强。通过对黑潮南海流套入侵较强的1999年2月与流套入侵较弱的1998年2月的SST卫星遥感资料的对比分析,考察了黑潮南海流套的入侵对南海北部陆架温度锋的影响,结果表明黑潮流套的较强入侵能够增加陆架温度锋的强度,对温度锋的走向也会产生一定的影响。 相似文献
105.
南海中部海区次表层NO2^——N的最大值 总被引:1,自引:0,他引:1
本文根据1983年9月至1985年1月南海中部海区综合调查所获得的NO_2~--N及有关参数的观测资料,分析了该海区NO_2~--N的分布变化特征及其与环境因子的关系。结果表明,调查海区NO_2~--N含量的变化范围在0~0.54μmol/L之间,其中小于0.05μmol/L的测定值约占测定总数的82.1%,而大于0.05μmol/L测定值基本上出现在50~150m层。文中还对该海区次表层NO_2~--N最大值形成的机理作了初步探讨,指出密度跃层的终年存在、铵的氧化和浮游植物的代谢过程是调查海区次表层NO_2~--N最大值形成的主要因素。 相似文献
106.
The North Yellow Sea Basin ( NYSB ), which was developed on the basement of North China (Huabei) continental block, is a typical continental Mesozoic Cenozoic sedimentary basin in the sea area. Its Mesozoic basin is a residual basin, below which there is probably a larger Paleozoic sedimentary basin. The North Yellow Sea Basin comprises four sags and three uplifts. Of them, the eastern sag is a Mesozoic Cenozoic sedimentary sag in NYSB and has the biggest sediment thickness; the current Korean drilling wells are concentrated in the eastern sag. This sag is comparatively rich in oil and gas resources and thus has a relatively good petroleum prospect in the sea. The central sag has also accommodated thick Mesozoic-Cenozoic sediments. The latest research results show that there are three series of hydrocarbon source rocks in the North Yellow Sea Basin, namely, black shales of the Paleogene, Jurassic and Cretaceous. The principal hydrocarbon source rocks in NYSB are the Mesozoic black shale. According to the drilling data of Korea, the black shales of the Paleogene, Jurassic and Cretaceous have all come up to the standards of good and mature source rocks. The NYSB owns an intact system of oil generation, reservoir and capping rocks that can help hydrocarbon to form in the basin and thus it has the great potential of oil and gas. The vertical distribution of the hydrocarbon resources is mainly considered to be in the Cretaceous and then in the Jurassic. 相似文献
107.
南海北部水体叶绿素a浓度反演的生物光学模型 总被引:2,自引:0,他引:2
利用2003年至2005年秋季在南海多个航次的现场观测数据,研究了南海北部海区遥感反射率的变化,并分析了用于全球海洋叶绿素a浓度反演的OC2和OC4模型在本海区的适用性。结果表明,在南海北部海域,OC2和OC4模型高估了叶绿素a浓度,高估范围一般约在80%—200%之间,其中最高可达640%,即OC2和OC4模型并不适用于南海海域。在此基础上,根据现场实测的表观光学数据,利用遥感反射率比值(Rrs(433)/Rrs(555))与叶绿素a浓度的关系建立了两套能够精确反演南海北部海域叶绿素a浓度的本地化经验算法———算法1和算法2,并利用其对南海北部海域的叶绿素a浓度进行反演。结果表明,由本地化模型反演得到的叶绿素a浓度与实测的叶绿素a浓度具有较好的相关关系,其平均相对偏差分别为51%和53%,相关系数为0.75。 相似文献
108.
109.
南沙群岛海区晚第四纪碳酸盐沉积 总被引:1,自引:0,他引:1
本文研究了五个柱状沉积物的碳酸盐沉积。根据沉积物的陆源碎屑和生物骨屑CaCO3沉积作用的特点,把本区沉积物分为五种沉积类;碳酸盐生物组成的门类较多,以有孔虫为主,其次为珊瑚,腹足类等;碳酸盐矿物以低镁方解石为主,还有高镁方解石和文石;与沉积物中CaCO3有关的化学元素10多种。这些元素和稀土元素的含量,比值等,是区分礁相,礁体过渡带和非礁相的标志。所有这些碳酸盐沉积作用的特点表明,区内存在着五种沉 相似文献
110.
A Stable Carbon Isotope Study of the Food-web in a Freshwater-deprived South African Estuary, with Particular Emphasis on the Ichthyofauna 总被引:1,自引:0,他引:1
The importance of macrophytes as food sources for estuarine nekton is unclear. Previous carbon isotope investigations in the macrophyte-dominated, freshwater-deprived Kariega Estuary showed that the bivalveSolen cylindraceusdid not utilize the dominant estuarine macrophytes found within the estuary as a primary food source. This finding prompted questions as to what the nekton of this estuary utilize as primary energy sources. δ13C analyses of the principal autochthonous and allochthonous primary carbon sources, as well as the dominant invertebrate and fish species, indicate that there are two main carbon pathways within the Kariega Estuary. The littoral community, which incorporates the majority of crustaceans, gobies, mullet and a sparid, utilizes δ13C enriched primary food sources namelySpartina maritima,Zosteracapensis and epiphytes. The channel fauna, which includes the zooplankton, zooplanktivorous and piscivorous fish, utilizes a primary food source depleted in δ13C, which is most likely a mixture of phytoplankton, terrestrial plant debris and C4macrophyte detritus. The C3saltmarsh macrophytesSarcocornia perennisandChenolea diffusa, as well as benthic microalgae, appear to be less important as primary food sources to the nekton of the Kariega Estuary. 相似文献